设计模式-建造者模式

发布于:2024-12-18 ⋅ 阅读:(96) ⋅ 点赞:(0)

建造者模式UML类图

Product :代表要构建的复杂对象,包含一个parts列表来存储构建的部件,并有addshow方法来添加部件和展示产品

Builder:是抽象建造者角色,定义了构建产品的方法,并返回自身以支持链式调用

ConcreteBuilder:是具体建造者角色,实现了Builder中定义的方法,构建产品的具体部分

Director:是指挥者角色,负责安排构建过程,并使用Builder来构建产品

ConcreteBuilder:继承自BuilderDirector:使用Builder来构建产品

一、产品角色(Product)

import java.util.ArrayList;
import java.util.List;

public class Product {
    private List<String> parts;

    public Product() {
        this.parts = new ArrayList<>();
    }

    public void add(String part) {
        parts.add(part);
    }

    public void show() {
        System.out.println("------------");
        for (String part : parts) {
            System.out.println(part);
        }
        System.out.println("------------");
    }
}

二、抽象建造者角色(Builder)

public abstract class Builder {
    protected Product product = new Product();

    public abstract Builder buildPartA();

    public abstract Builder buildPartB();

    public Product build() {
        return product;
    }
}

三、具体建造者角色(ConcreteBuilder)

public class ConcreteBuilder extends Builder {
    @Override
    public Builder buildPartA() {
        product.add("PartA");
        return this;
    }

    @Override
    public Builder buildPartB() {
        product.add("PartB");
        return this;
    }
}

四、指挥者角色(Director)

public class Director {
    private Builder builder;

    public Director(Builder builder) {
        this.builder = builder;
    }

    public void construct() {
        builder.buildPartA().buildPartB();
    }

    public Product getProduct() {
        return builder.build();
    }
}

五、测试

public class Client {
    public static void main(String[] args) {
        Director director = new Director(new ConcreteBuilder());
        director.construct();
        Product product = director.getProduct();
        product.show();
    }
}

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